ANNELID GENUS CAJMBARINCOLA — HOFFMAN 305 



Affinities. — In general body form, jaw structure, and great size 

 of the prostate, this species is obviousl}^ allied to mesochorea,with. which 

 it is apparently sjanpatric. The major difference between the two 

 lies in the large and distinct posterior deferent lobe of ouachita, and by 

 the fact that the anterior lobe is somewhat longer than the prostate. 

 Whether we are dealing here ^vith two distinct species, or the local 

 recrudescence of a primitive character wdthin a population of mesocho- 

 rea is something to be settled by future study of the Kansas-Oldahoma 

 branchiobdellid fauna. 



Cambarincola restarts, new species 



Figures 7, 10 



Type specimens. — Holotype and two para types, USNM 29938, 

 from Orconedes sp. taken in Sugar Creek, 2 miles north of Avoca, 

 Benton County, Arkansas by P. C. Holt, July 6, 1958. Topopara- 

 t3T)es, PCH 768. 



Diagnosis. — ^A species of the Alesochorea group, distinguished not 

 only from its close relatives but from all other species of the genus by 

 the accentuated head size and small body. 



Description. — A moderatel}'" large worm, maximum length about 

 3.5 mm., the body form unusual in not being appreciably enlarged 

 near the midlength, but of essentially the same diameter througliout, 

 the caudal sucker a little larger in diameter than the preceding few 

 segments. Prosomites about twice as long as metasomites, but the 

 two subsegments of about the same diameter. 



Head enormously developed, about as long as the fu-st five segments 

 combined and half again as broad as the greatest body diameter. 

 Peristomium rather small, less than a third of the total head length, 

 and not flared, divided into dorsal and ventral halves ^vith a small 

 lobe at the lateral sinus on each side but the peristomial margin not 

 lobed. Head broadest at its midlength, tapering slightly toward the 

 ends, the diameter about 75 percent of the length. 



Jaws anisomorphic, subhomodont, the dental formula 5-4; the 

 lateral cusps not appreciably smaller than the dorsal median and 

 ventral paramedian teeth. 



Male reproductive system similar to that of mesochorea in most 

 respects, but the prostate not noticeably longer than the spermiducal 

 gland, both somewhat arched in the coelom with the ectal end of the 

 latter drawn ventrad by the ejaculatory duct (perhaps also by the 

 pressure of the rather short segment). Prostate a little greater in 

 diameter than spermiducal gland, its size increasing a little entaUy, 

 terminating in a bluntly clavate lobe. Ental end of spermiducal 

 gland T shaped, both deferent ducts entering at about the same angle, 

 into very weakly developed deferent lobes. Exact shape of bursa not 



